He subsequently wrote or co-wrote three Doctor Who spin-off novels in the Virgin PublishingNew Adventures range; he created the character Kadiatu Lethbridge-Stewart who became a semi-regular in the New Adventures. He has also written a novel and several short stories published by Big Finish Productions featuring the character of Bernice Summerfield, who was originally developed in the New Adventures. He also co-wrote a Doctor Who audio drama for Big Finish, and has written a number of Blake's 7 spin-off audio dramas.